9.22.20 Lesson #4 Pancreas, Liver, Gallbladder
On our way south in the digestive process, there are few organs outside of the digestive tract that have a huge impact on how well we can break down our food and absorb nutrients! These include the pancreas, the liver, and the gallbladder. These 3 organs have ducts that empty into the first part of the small intestine. Our half digested food at this point is now called chyme.
The bulk of our pancreas is in the center of our upper abdomen with a finger like portion going left behind our stomach. The pancreas makes a juice that is piped to the first part of our small intestine, joining the pipeline from the liver and gallbladder. This juice is made of water, salt, sodium bicarbonate, and enzymes (Tortora and Derrickson 2015). This combination makes the chyme less acidic, inactivates the pepsin and makes a more friendly environment for enzymes to start working. It is quite amazing that the protein digesting enzymes are released from the pancreas in an inactive form - otherwise they would start digesting your pancreas right away! There are also enzymes from the pancreas that break down fats, starches, and carbohydrates.
Your liver is one of the most fascinating organs! At about 3 lbs, this is the second largest organ in your body! (Leave a comment if you know the largest organ!) It has many different functions in the body but the main ones involving digestion are the enzymes it makes. These enzymes are important for carbohydrate metabolism (think glucose), breaking down fats (think how soap works on greasy dishes), and breaking down protein. Another interesting component that the liver makes is bilirubin. This is made from parts of old red blood cells. The liver secretes it with the bile, it feeds bacteria in the small intestine, and then the by-product of that is what makes our poop brown!
The gallbladder is like a little balloon on the way from the liver to the duodenum. It is a storage sac for bile from the liver. It concentrates the bile and then releases it when there is chyme (½ digested food) present. There is another sphincter where this duct enters the duodenum that holds back the bile and pancreatic juices until needed.